Rotary engine anti-spin oil seal

ABSTRACT

A rotary engine anti-spin oil seal arrangement has a lock tab that is detachably secured to and projects from an unsealed radially facing side of the oil seal and catches in a lock groove in the radially oppositely facing wall of the oil seal groove in the rotor to prevent the oil seal from spinning in the oil seal groove without interfering with the normal sealing action.

United States Patent 1191 Rose Dec. 9, 1975 [5 ROTARY ENGINE ANTI-SPIN OIL SEAL 3,575,541 4/1971 l-lamada 418/142 Inventor DaleP Rose Howell Mich Rl8,776 3/1933 McMinn et al. 277/136 [73] Assignee: General Motors Corporation, FOREIGN PATENTS OR APPLICATIONS Detroit i 860,740 10/1940 France 277/137 1,233,198 l/l967 Germany 418/142 [22] Filed: Dec. 13, 19173 [2]] Appl 424,572 Primary Examiner.lohn J. Vrablik Attorney, Agent, or Firm-R0na]d L. Phillips [44] Publlshed under the Tnal Voluntary Protest Erzggag; January 28, 1975 as document no. [57] ABSTRACT A rotary engine anti-spin oil seal arrangement has a 52 US. Cl. 418/142 leek tab that is detaehably secured to and projects 51 1m. 01. ..F01C 19/00; F04C 15/00; from an unsealed radially facing ide of he oil seal F04C 27/00 and catches in a lock groove in the radially oppositely 58 Field of Search 418/142; 277/136, 137 ng wall of the oil seal groove in the rotor to p vent the oil seal from spinning in the oil seal groove [56] References Cited without interfering with the normal sealing action.

UNITED STATES PATENTS 4 Claims, 7 Drawing Figures 3,193,188 7/1965 Bentele 418/142 US. Patent Dec. 9, 1975 ROTARY ENGINE ANTI-SPIN OIL SEAL This invention relates to a rotary engine anti-spin oil seal arrangement and more particularly to such an arrangement employing a simple lock tab.

In the presently commercial rotary engine having a' two-lobe internal peripheral wall and a three-lobe planetary rotor, a pair of circular oil seals are mounted in each side of the rotor and are biased by wave springs to sealingly engage stationary side walls. In addition, sealing between each oil seal and the rotor is provided by an elastomeric O-ring which is mounted in an annular groove in either the inwardly or outwardly facing side of the oil seal and sealingly engages the oppositely facing wall of the oil seal groove. It has been found that without some preventative provision the oil seals can spin in their grooves during engine operation with the undesirable result that there will occur relative rotation either between the oil seal and the O-ring or between the O-ring and the wall of the groove that it engages. In either event, this spinning abrades the elastomeric O- ring and thus impairs its sealing effectiveness. Thus, it is desirable that the oil seals be prevented from spinning in their oil seal grooves. However, any such anti-spin device should not interfere with the normal sealing action and yet be simple and inexpensive.

An object of the present invention is to provide a new and improved rotary engine anti-spin oil seal arrangement.

Another object is to provide a rotary engine anti-spin oil seal arrangement having a simple lock tab that readily secures to the oil seal and catches in a lock groove in an unsealed wall of the oil seal groove in the rotor to prevent the oil seal from turning in the oil seal groove while permitting normal oil seal movement.

Another object is to provide a rotary engine oil seal arrangement having a lock tab that is detachably secured to and projects from an unsealed side of the oil seal but does not interfere with an elastomeric seal mounted in a groove in a sealed side of the oil seal and catches on oil seal installation in a lock groove in the oppositely facing wall of the oil seal groove in the rotor to prevent the oil seal from spinning in the oil seal groove while permitting normal movement of the oil seal.

These and other objects of the present invention will be more apparent from the following description and drawing in which:

FIG. 1 is a longitudinal view with parts in section of a rotary engine having anti-spin oil seal arrangements constructed according to the present invention.

FIG. 2 is a view taken along the line 2-2 in FIG. 1 showing one rotor side.

FIG. 3 is an enlarged view of the anti-spin oil seal arrangements as shown in FIG. 2.

FIG. 4 is a view taken along the line 4-4 in FIG. 3.

FIG. 5 is a perspective view with parts broken away showing the lock tab arrangement.

FIG. 6 is a perspective view with parts broken away and exploded showing another embodiment of the lock tab.

FIG. 7 is a view similar to FIG. 6 showing another embodiment of the lock tab.

The present invention is for use in a rotary combustion engine of the planetary type shown in FIGS. 1 and 2. The engine comprises a housing 10 which in a single rotor arrangement, as shown, has basically three parts;

namely; a rotor housing 12 having an inwardly facing inner peripheral wall 14 and a pair of side housings 16 and 18 having parallel, oppositely facing, spaced inner side walls 20 and 22, respectively. The housing parts are secured together by bolts, not shown, and the inner housing walls 14, 20 and 22 cooperatively provide a cavity 24. As shown in FIG. 2, the peripheral wall 14 is a two-lobe curve with a center line indicated at 26. A crankshaft 28 extends through the cavity and is rotatably supported in sleeve bearings 30 and 32 which are secured in collars 34 and 36 that are bolted to the side housings l6 and 18, as shown in FIG. 1, the crankshaft axis being coincident with the center line 26, parallel to the peripheral wall 14 and at right angles to the side "walls 20 and 22. The crankshaft 28 is provided in cavity 24 with an eccentric 38. A three-lobe rotor 40 has a hub 41 having a sleeve bearing 42 secured therein which is received on the eccentric 38 so that the rotor is thereby supported in cavity 24 for rotation about the eccentric s center line 44 which is thus the rotors axis. The rotor 40 has the general shape of an arcuate sided triangle with two parallel sides 46 and 48 at right angles to the rotor axis which face and run close to the side walls 20 and 22, respectively, and an outer peripheral wall having three arcuate outer faces 50 which face the peripheral wall 14 and cooperate therewith and with the side walls 20 and 22 to define three variable volume working chambers 52. Sealing of these chambers is effected by gas sealing means comprising three apex seals 54 which are each mounted in an axially extending groove or slot at each apex or corner of the rotor 40 and extend the width thereof. Three arcuate side seals 56 are mounted in accommodating grooves in each rotor side and extend adjacent the rotor faces between two of the apex seals 54. Three cylindrical corner seals 58 are mounted in cylindrical blind bores in each rotor side contiguous with the apex seal slots with each comer seal having a slot receiving one end of an apex seal and providing sealing, between the ends of two side seals and one apex seal as shown in FIG. 2. The apex seals 54 are spring biased to engage the peripheral wall 14 and both the side seals 56 and the corner seals 58 are spring biased toengage the respective side walls 20 and 22 with the complete gas seal arrangement acting to seal the working chambers.

With the two-lobe peripheral wall 14 and the threelobe rotor 40, each of the working chambers 52 sequentially expands and contracts between minimum and maximum volume twice during each revolution while the rotor apexes closely follow the peripheral wall by forcing the rotor to rotate at one-third the speed of the crankshaft. This is accomplished by gearing comprising an internal tooth gear 62 which is formed integral with the righthand side 48 of the rotor with its center on the rotor axis. The gear 62 meshes 'with an external tooth annular gear 64 which is freely received about and is concentric with the crankshaft 28 and is made stationary by being formed integral with the left-hand end of the right-hand collar 36 as shown in FIG. 1. The gear 62 has one and one-half times the number of teeth as the gear 64 to provide the required speed ratio of 3:1 between the crankshaft and the rotor.

A combustible air-fuel mixture from a suitable carburetor arrangement, not shown, is made available to each working chamber 52 by an intake passage 66 as shown in FIG. 2. Intake passage 66 extends through the engine housing and opens to the cavity through either the peripheral wall 14 or through aligned side wall ports 67, only one of which is shown, or through a combination thereof with such porting being located on the leading side of cusp 68 of the peripheral wall relative to the direction of rotor rotation indicated by the arrow in FIG. 2. Thus, the rotor sides uncover the intake ports to the chambers as they are expanding in the intake phase to draw in the combustible mixture and then closes this intake opening to them when they are contracting to compress the mixture in the following compression phase. A single channel or recess 69 is provided in the center of each chamber face of the rotor so that when each rotor face is at or near its top-dead-center position with its center opposite the peripheral walls other cusp 70, the associated chamber is not then divided by this cusp. A spark plug 72 is mounted in the rotor housing 12 adjacent the cusp 70 with its electrodes exposed to the passing working chambers and is supplied with voltage from a suitable ignition system, not shown, at the proper time at or near top-dead-center to initiate combustion at the end of the compression phase. On combustion the peripheral wall 14 takes the reaction forcing the rotor to continue rotating while the gas is expanding in the expansion or power phase. The leading apex seal 54 of the working chambers eventually traverses an exhaust passage 74 in the rotor housing on the trailing side of the cusp 68 whereby the exhaust products are then expelled in the exhaust phase to complete the cycle.

Describing now the lubrication and also the cooling of the rotor that is normally provided in such an arrangement, oil from the engine drains to a sump from which it is delivered by a suitable engine powered pump, not shown, to a central axial oil passage 86 in the crankshaft 28 as shown in FIG. 1. Radial oil passages 88, 90 and 92 deliver oil from the passage 86 to lubricate the sleeve bearings 30, 42 and 32, respectively. The rotor 40 has a hollow interior and is webbed for rigidity and a radial oil passage 94 in the crankshaft 28 delivers oil from the passage 86 to lubricate the gears 62 and 64 and also to the rotors interior for cooling of the rotor with the oil carrying the heat from the rotor by passing to annular cavities 96 and 98 in the respective side walls 20 and 22 that are connected by passages, not shown, to drain to the sump. In addition to the gas seals carried on the rotor 40, there is provided in each side of the rotor inner and outer circular oil seals 100 and 102 of metal that are located radially inwardly of the side seals 56 in accommodating axially outwardly facing circular grooves 104 and 106, respectively, that are centered on the rotor axis 44. As best shown in FIG. 4, the oil seals 100 and 102 in each rotor side are biased to engage the oppositely facing housing side wall to prevent the oil supplied for lubrication and cooling from reaching the radially outwardly located gas seals by split annular wave springs 108 and 1 that engage on one spring side with the oil seal grooves planar bottoms 112 and 114 and on the other spring side with the oil seals planar backsides 116 and 118, respectively. In addition, sealing is provided between the oil seals 100 and 102 and the rotor by elastomeric 0- rings 120 and 122 which are mounted in annular grooves 124 and 126 in the radially outwardly and inwardly facing sides 128 and 130 of the respective oil seals 100 and 102, these grooves being rectangular in cross-section. The O-ring grooove 124 in the inner oil seal 100 faces radially outwardly with the O-ring 120 engaging the oppositely radially. facing wall 132 of the oil seal groove 104. Conversely, the O-ring groove 126 in the outer oil seal 102 faces radially inwardly with the O-ring 122 engaging the oppositely radially facing wall 134 of the oil seal groove 106. Thus, the O-rings and 122 seal the respective radial clearances 136 and 138 between the oil seals 100 and 102 and the oil seal groove walls 132 and 134 while the radial clearances 140 and 142 between the other radially facing oil seal sides 144 and 146 and oil seal groove walls 148 and 150 are left open. Thus, in the case of the outer oil seal 102, gas pressure past the side seals 56 can pass through clearance 142 on this unsealed oil seal side but is trapped by the O ring sealed oil seal side to act behind this oil seal to assist the spring bias while in the case of the inner oil seal 100, oil can pass through the clearance 140 on this unsealed oil seal side but is trapped in the chamber behind this oil seal by the O-ring sealed oil seal side so that with centrifugal action there is developed oil pressure to assist the spring bias on this oil seal.

The structure thus far described is conventional and without some anti=spin provision the oil seals can spin in their grooves causing impairment of the sealing effectiveness of the O-rings. Such adverse effect is positively prevented by the present invention with only a simple lock tab and simple modifications to the oil seals and oil seal grooves which do not adversely affect the normal sealing action. To prevent oil seal spin, there are provided cylindrical lock grooves 152 and 154 which are drilled-in the unsealed walls 148 and 150 of the oil seal grooves 104 and 106 parallel to the groove center line 44 as shown in FIGS. 3 and 4. The lock grooves 152 and 154 extend to the bottoms 112 and 114 of the oil seal grooves 104 and 106 as shown in FIG. 4 and each receive a lock tab 156 that is secured to each of the respective oil seals 100 and 102. In the form shown in FIGS. 2, 3, 4 and 5, each of the lock tabs 156 is formed of wire and as fabricated has a simple U- shape, as shown in broken line in FIG. 5, with legs 158 that are then parallel to permit assembly. In the case of the inner oil seal 100 radial holes 160 are drilled through the unsealed radially inwardly facing side 144 with these holes positioned close to the rearward corner of the O-ring groove 124 and being angularly spaced to receive the lock tab legs 158. The legs 158 of the lock tab 156 are inserted from the unsealed side 144 of the oil seal through the holes 160 with the bight 162 of the tab projecting radially inwardly of the oil seal 100 on the unsealed side. The legs 158 are then bent in opposite angular directions to fit along the rearward corner of groove 124. This positively secures the lock tab 156 to the oil seal wherefter the O-ring 120 may be inserted in the O-ring groove 124 in the normal manner since the lock tab legs 158 are in locations so as not to interfere therewith. The oil seal 100 is then inserted in the oil seal groove 104 in the rotor with the bight 162 of the lock tab 156 fitting in the lock groove 152. The lock groove 152 captures the bight 162 of the lock tab 156 to prevent the oil seal 100 from spinning in the oil seal groove 104 but because of the lock groove alignment with the normal direction of seal movement permits the bight 162 to move therealong so that the oil seal 100 remains free to move axially to maintain sealing engagement with the housing side wall. Since the lock tab 156 is located in a most rearward location, there is no reasonable possibility that it will leave the lock groove during the life of the oil seal. Thus,-the lock tab 156 does not interfere with the normal sealing action of either the O-ring 120 or the oil seal 100. Similar locking without seal interference is provided for the outer oil seal 102 as shown in FIGS. 2, 3 and 4 recognizing that in this case the unsealed side of the outer oil seal 102 is the radially outwardly facing side 146 and that the lock tab holes in the oil seal are through this side and that the outer lock tab 156 projects from this oil seal side to engage the lock groove 154 in the unsealed wall 150 of the outer oil seal groove 106.

In FIG. 6 wherein structure similar to that previously described is identified by the same numbers only primed and substantially different structure is described by different numbers, there is shown another embodiment of the lock tab which is also of wire but does not require any further forming for retention on the oil seal. In this case the lock tab 156 has a fabricated -shaped and instead of radially drilled holes in the oil seal there is provided a single slot 160' through the unsealed side 144 of the oil seal that is in the same location as the drilled holes with its width slightly larger than that of the wire diameter and a length measured in the angular direction that is smaller than the free or unsprung dimension A measured across the widest portion of the bight 162'. To assemble the lock tab 156 the preformed legs 158' are compressed in angularly opposite directions to reduce the size of the bight 162 sufficiently to permit its entry into the slot 160' from the O-ring groove side whereafter on release of this assembly force the lock tab is held by the added oppositely facing detent bends 164 which catch the opposite ends 166 of the slot 160'. With the lock tab 156' thus detachably secured on the oil seal, the bight 162 operates in the lock groove in the oil seal groove in the rotor as previously described to prevent oil seal spin while not interfering with the sealing action.

In FIG. 7 there is shown another embodiment of the lock tab which like the FIG. 6 embodiment does not require any additional forming for retention on the oil seal and wherein similar structure is identified by the same numbers only double primed and substantially different structure is identified by different numbers. In the FIG. 7 embodiment the lock tab 156" is stamped from sheet metal and has a rounded head 162" which fits through the slot 160" in the unsealed side 144" of the oil seal and also has a single transversely extending leg 158" which is of longer dimension than the length of the lock slot 166" that is fully received in and along the one wall of the O-ring groove. The head 162 has locking ears 168 that project out of the normal plane of i the tab and are deflected into this plane to permit insertion of the head and ears through the slot 166 whereafter the ears spring back to their nonnal angle to prevent removal of the lock tab and together with the leg 158" positively hold the lock tab on the oil seal. With the lock tab 158 thus securely attached to the oil seal, the head 162" operates in the lock groove in the oil seal groove in the rotor as previously described to prevent oil seal spin while permitting normal oil seal action.

The above described embodiments are illustrative of the invention which may be modified within the scope of the appended claims.

I claim:

1. A rotary engine having a housing with an inwardly facing peripheral wall and oppositely facing inner side walls cooperatively defining a cavity, a crankshaft rotatably supported in said housing, said crankshaft having an eccentric located in said cavity, a rotor rotatably mounted on said eccentric in said cavity, said rotor having sides facing said side walls and peripheral faces facing said peripheral wall defining a plurality of chambers that are spaced about and move with said rotor while varying in volume as said rotor rotates, a circular groove to sealingly engage the opposite housing side wall, an elastomeric seal groove in one of said radially facing sides of said oil seal, said elastomeric seal groove having a radially facing bottom opposite one of the walls of said oil seal groove and radially extending oppositely facing walls, an elastomeric seal mounted in said elastomeric seal groove in said oil seal and engaging the bottom of said elastomeric seal groove and the oppositely radially facing said one wall of said oil seal groove to provide sealing between said oil seal and said rotor while said oil seal sealingly engages the housing side wall, lock tab means secured in an aperture through the bottom and adjacent one corner of said elastomeric seal groove in said oil seal out of the way of said elastomeric seal and projectingradially past the unsealed other radially facing side of said oil seal, and a lock groove in the unsealed wall of said oil seal groove in said rotor aligned with the normal direction of oil seal movement for receiving said lock tab to prevent said oil seal from spinning in said oil seal groove while permitting said lock tab to move with said oil seal in the normal direction in said oil seal groove so that said oil seal remains free to move axially to maintain sealing engagement with the opposite housing side wall.

2. A rotary engine having a housing with an inwardly facing peripheral wall and oppositely facing inner side walls cooperatively defining ,a cavity, a crankshaft rotatably supported in said housing, said crankshaft having an eccentric located in said cavity, a rotor rotatably mounted on said eccentric in said cavity, said rotor having sides facing said side walls and peripheral faces groove bottom and said oil seal backside for biasing said oil seal to normally move axially in said oil seal groove to sealingly engage the opposite housing side wall, an elastomeric seal groove in one of said radially facing sides of said oil seal, said elastomeric seal groove having a radially facing bottom opposite one of the walls of said oil seal groove and radially extending oppositely facing walls, an elastomeric seal mounted in said elastomeric seal groove in said oil seal and engaging the bottom of said elastomeric seal groove and the oppositely radially facing said one wall of said oil seal groove to provide sealing between said oil seal and said rotor while said oil seal sealingly engages the housing side wall, a wire lock tab having two legs received in holes through the bottom and adjacent one corner of said elastomeric seal groove in said oil seal with the legs bent to fit along said one comer out of the way of said elastomeric seal, said lock tab further having a bight projecting radially past the unsealed other radially facing side of said oil seal, and a lock groove in the unsealed wall of said oil seal groove in said rotor aligned with the normal direction of oil seal movement for receiving said bight to prevent said oil seal from spinning in said oil seal groove while permitting said lock tab to move with said oil seal in the normal direction in said oil seal groove so that said oil seal remains free to move axially to maintain sealing engagement with the opposite housing side wall.

3. A rotary engine having a housing with an inwardly facing peripheral wall and oppositely facing inner side walls cooperatively defining a cavity, a crankshaft rotatably supported in said housing, said crankshaft having an eccentric located in said cavity, a rotor rotatably mounted on said eccentric in said cavity, said rotor having sides facing said side walls and peripheral faces facing said peripheral wall defining a plurality of chambers that are spaced about and move with said rotor while varying in volume as said rotor rotates, a circular oil seal groove in each side of said rotor with its center on the rotor axis, a circular oil seal in each said oil seal groove axially movable to sealingly engage the opposing side wall, said oil seal having a backside and oppositely radially facing sides, said oil seal groove having a bottom and oppositely radially facing walls, a wave spring mounted in said oil seal groove engaging said groove bottom and said oil seal backside for biasing said oil seal to normally move axially in said oil seal groove to sealingly engage the opposite housing side wall, an elastomeric seal groove in one of said radially facing sides of said oil seal, said elastomeric seal groove having a radially facing bottom opposite one of the walls of said oil seal groove and radially extending oppositely facing walls, an elastomeric seal mounted in said elastomeric seal groove in said oil seal and engaging the bottom of said elastomeric seal groove and the oppositely radially facing said one wall of said oil seal groove to provide sealing between said oil seal and said rotor while said oil seal sealingly engages the housing side wall, a wire lock tab having a lock bight compressibly received through a slot in the bottom and adjacent one corner of said elastomeric seal groove in said oil seal and also having a pair of oppositely facing detent bends that catch the opposite ends of said slot and are out of the way of said elastomeric seal, said lock bight projecting radially past the unsealed other radially facing side of said oil seal, and a lock groove in the unsealed wall of said oil seal groove in said rotor aligned with the normal direction of oil seal movement for receiving said lock bight to prevent said oil seal from spinning in said oil seal groove while permitting said lock tab to move with said oil seal in the normal direction in said oil seal groove so that said oil seal remains free to move axially to maintain sealing engagement with the opposite housing side wall.

4. A rotary engine having a housing with an inwardly facing peripheral wall and oppositely facing inner side walls cooperatively defining a cavity, a crankshaft rotatably supported in said housing, said crankshaft having an eccentric located in said cavity, a rotor rotatably mounted on said eccentric in said cavity, said rotor having sides facing said side walls and peripheral faces facing said peripheral wall defining a plurality of chambers that are spaced about and move with said rotor while varying in volume as said rotor rotates, a circular oil seal groove in each side of said rotor with its center on the rotor axis, a circular oil seal in each said oil seal groove axially movable to sealingly engage the opposing side wall, said oil seal having a backside and oppositely radially facing sides, said oil seal groove having a bottom and oppositely radially facing walls, a wave spring mounted in said oil seal groove engaging said groove bottom and said oil seal backside for biasing said oil seal to normally move axially in said oil seal groove to sealingly engage the opposite housing side wall, an elastomeric seal groove in one of said radially facing sides of said oil seal, said elastomeric seal groove having a radially facing bottom opposite one of the walls of said oil seal groove and radially extending oppositely facing walls, an elastomeric seal mounted in said elastomeric se'al groove in said oil seal and engaging the bottom of said elastomeric seal groove and the oppositely radially facing said one wall of said oil seal groove to provide sealing between said oil seal and said rotor while said oil seal sealingly engages the housing side wall, a lock tab having a head with deflectable ears deflectively received through a slot in the bottom and adjacent one comer of said elastomeric seal groove in said oil seal and also having a transverse leg longer than said slot that is received in said elastomeric seal groove out of the way of said elastomeric seal, said head projecting radially past the unsealed other radially facing UNITED STATES PATENT AND TRADEMARK OFFICE CERTIFICATE OF CORRECTION PATENT NO. ,924,979 I Q DATED December 9, 1975 |NVENTOR( 1 Dale P. Rose It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 5, line 17, "-shaped" should read z -shaped Signed and Scaled this Thirty-first Day Of August 1976 Arrest:

RUTH C. MASON C. MARSHALL DANN Arresting Officer Commissioner oj'laremx and Trademarkx 

1. A rotary engine having a housing with an inwardly facing peripheral wall and oppositely facing inner side walls cooperatively defining a cavity, a crankshaft rotatably supported in said housing, said crankshaft having an eccentric located in said cavity, a rotor rotatably mounted on said eccentric in said cavity, said rotor having sides facing said side walls and peripheral faces facing said peripheral wall defining a plurality of chambers that are spaced about and move with said rotor while varying in volume as said rotor rotates, a circular oil seal groove in each side of said rotor with its center on the rotor axis, a circular oil seal in each said oil seal groove axially movable to sealingly engage the opposing side wall, said oil seal having a backside and oppositely radially facing sides, said oil seal groove having a bottom and oppositely radially facing walls, a wave spring mounted in said oil seal groove engaging said groove bottom and said oil seal backside for biasing said oil seal to normally move axially in said oil seal groove to sealingly engage the opposite housing side wall, an elastomeric seal groove in one of said radially facing sides of said oil seal, said elastomeric seal groove having a radially facing bottom opposite one of the walls of said oil seal groove and radially extending oppositely facing walls, an elastomeric seaL mounted in said elastomeric seal groove in said oil seal and engaging the bottom of said elastomeric seal groove and the oppositely radially facing said one wall of said oil seal groove to provide sealing between said oil seal and said rotor while said oil seal sealingly engages the housing side wall, lock tab means secured in an aperture through the bottom and adjacent one corner of said elastomeric seal groove in said oil seal out of the way of said elastomeric seal and projecting radially past the unsealed other radially facing side of said oil seal, and a lock groove in the unsealed wall of said oil seal groove in said rotor aligned with the normal direction of oil seal movement for receiving said lock tab to prevent said oil seal from spinning in said oil seal groove while permitting said lock tab to move with said oil seal in the normal direction in said oil seal groove so that said oil seal remains free to move axially to maintain sealing engagement with the opposite housing side wall.
 2. A rotary engine having a housing with an inwardly facing peripheral wall and oppositely facing inner side walls cooperatively defining a cavity, a crankshaft rotatably supported in said housing, said crankshaft having an eccentric located in said cavity, a rotor rotatably mounted on said eccentric in said cavity, said rotor having sides facing said side walls and peripheral faces facing said peripheral wall defining a plurality of chambers that are spaced about and move with said rotor while varying in volume as said rotor rotates, a circular oil seal groove in each side of said rotor with its center on the rotor axis, a circular oil seal in each said oil seal groove axially movable to sealingly engage the opposing side wall, said oil seal having a backside and oppositely radially facing sides, said oil seal groove having a bottom and oppositely radially facing walls, a wave spring mounted in said oil seal groove engaging said groove bottom and said oil seal backside for biasing said oil seal to normally move axially in said oil seal groove to sealingly engage the opposite housing side wall, an elastomeric seal groove in one of said radially facing sides of said oil seal, said elastomeric seal groove having a radially facing bottom opposite one of the walls of said oil seal groove and radially extending oppositely facing walls, an elastomeric seal mounted in said elastomeric seal groove in said oil seal and engaging the bottom of said elastomeric seal groove and the oppositely radially facing said one wall of said oil seal groove to provide sealing between said oil seal and said rotor while said oil seal sealingly engages the housing side wall, a wire lock tab having two legs received in holes through the bottom and adjacent one corner of said elastomeric seal groove in said oil seal with the legs bent to fit along said one corner out of the way of said elastomeric seal, said lock tab further having a bight projecting radially past the unsealed other radially facing side of said oil seal, and a lock groove in the unsealed wall of said oil seal groove in said rotor aligned with the normal direction of oil seal movement for receiving said bight to prevent said oil seal from spinning in said oil seal groove while permitting said lock tab to move with said oil seal in the normal direction in said oil seal groove so that said oil seal remains free to move axially to maintain sealing engagement with the opposite housing side wall.
 3. A rotary engine having a housing with an inwardly facing peripheral wall and oppositely facing inner side walls cooperatively defining a cavity, a crankshaft rotatably supported in said housing, said crankshaft having an eccentric located in said cavity, a rotor rotatably mounted on said eccentric in said cavity, said rotor having sides facing said side walls and peripheral faces facing said peripheral wall defining a plurality of chambers that are spaced about and move with said rotor while varying in volume as said rotor rotates, a circular oil seal Groove in each side of said rotor with its center on the rotor axis, a circular oil seal in each said oil seal groove axially movable to sealingly engage the opposing side wall, said oil seal having a backside and oppositely radially facing sides, said oil seal groove having a bottom and oppositely radially facing walls, a wave spring mounted in said oil seal groove engaging said groove bottom and said oil seal backside for biasing said oil seal to normally move axially in said oil seal groove to sealingly engage the opposite housing side wall, an elastomeric seal groove in one of said radially facing sides of said oil seal, said elastomeric seal groove having a radially facing bottom opposite one of the walls of said oil seal groove and radially extending oppositely facing walls, an elastomeric seal mounted in said elastomeric seal groove in said oil seal and engaging the bottom of said elastomeric seal groove and the oppositely radially facing said one wall of said oil seal groove to provide sealing between said oil seal and said rotor while said oil seal sealingly engages the housing side wall, a wire lock tab having a lock bight compressibly received through a slot in the bottom and adjacent one corner of said elastomeric seal groove in said oil seal and also having a pair of oppositely facing detent bends that catch the opposite ends of said slot and are out of the way of said elastomeric seal, said lock bight projecting radially past the unsealed other radially facing side of said oil seal, and a lock groove in the unsealed wall of said oil seal groove in said rotor aligned with the normal direction of oil seal movement for receiving said lock bight to prevent said oil seal from spinning in said oil seal groove while permitting said lock tab to move with said oil seal in the normal direction in said oil seal groove so that said oil seal remains free to move axially to maintain sealing engagement with the opposite housing side wall.
 4. A rotary engine having a housing with an inwardly facing peripheral wall and oppositely facing inner side walls cooperatively defining a cavity, a crankshaft rotatably supported in said housing, said crankshaft having an eccentric located in said cavity, a rotor rotatably mounted on said eccentric in said cavity, said rotor having sides facing said side walls and peripheral faces facing said peripheral wall defining a plurality of chambers that are spaced about and move with said rotor while varying in volume as said rotor rotates, a circular oil seal groove in each side of said rotor with its center on the rotor axis, a circular oil seal in each said oil seal groove axially movable to sealingly engage the opposing side wall, said oil seal having a backside and oppositely radially facing sides, said oil seal groove having a bottom and oppositely radially facing walls, a wave spring mounted in said oil seal groove engaging said groove bottom and said oil seal backside for biasing said oil seal to normally move axially in said oil seal groove to sealingly engage the opposite housing side wall, an elastomeric seal groove in one of said radially facing sides of said oil seal, said elastomeric seal groove having a radially facing bottom opposite one of the walls of said oil seal groove and radially extending oppositely facing walls, an elastomeric seal mounted in said elastomeric seal groove in said oil seal and engaging the bottom of said elastomeric seal groove and the oppositely radially facing said one wall of said oil seal groove to provide sealing between said oil seal and said rotor while said oil seal sealingly engages the housing side wall, a lock tab having a head with deflectable ears deflectively received through a slot in the bottom and adjacent one corner of said elastomeric seal groove in said oil seal and also having a transverse leg longer than said slot that is received in said elastomeric seal groove out of the way of said elastomeric seal, said head projecting radially past the unsealed other radially facing side of said oil seal, and a lock groove in the unsealed wall of said oil seal groove in said rotor aligned with the normal direction of oil seal movement for receiving said head to prevent said oil seal from spinning in said oil seal groove while permitting said lock tab to move with said oil seal in the normal direction in said oil seal groove so that said oil seal remains free to move axially to maintain sealing engagement with the opposite housing side wall. 